Long Stroke Crankshaft MAZZU..

More stroke allows more cubic capacity, which in turn, means more power. That's why most 200er motors, whether race or road tuned, turn to long stroke crankshafts. To balance out stroke increase, spacers are set in either at the cylinder base or head. It's also a simple way to play around with timing.

With long stroke crankshafts, the stroke pivot is further from the crankcase axel: with 60 mm shafts, 1.5 mm. The additional 1.5 mm pushes over the top and lower dead center. To keep the piston from touching the cylinder head, cylinder head/base spacers can be installed or suitable SIP/MMW cylinder heads can be used. Timing changes in any case. Depending on type of race cylinder, there are several favored combinations which we've put together for you in the technical department.

1.5 mm head compensation: hefty torque and free wheelies in lower rpm's, lower top speeds. This is SIP's favorite touring combination, especially when coupled with a longer transmission.

The MAZZUCCHELLIlong stroke crankshafts have a substantially extended intake timing, just like the racing crankshafts. The conrod is partially a polished special edged conrod, and the lower conrod bearing is a silver bearing. It is also available as a strengthened 'K2D' version. The higher solidity of the K2D alloy means it is possible to achieve a higher pressing dimension on the crank pins. This means that the torsion resistance is also increased without welding. This material is now used on all MAZZUCHELLI full circle crankshafts.

SIP-TIP: SIP/MMW long stroke head, MALOSSI 210cc and SIP Road exhaust for touring set up, 1.5 mm base gasket, SIP Performance/RZ/DSE exhaust, MALOSSI or POLINI, 28-30 mm carburetor as basics for sport set up. Try out a variety of base/head gaskets to find the right one for your needs.

The timings stated above were determined viewing in the direction of the clutch side. That means: "138°/6° after TDC: Inlet timing begins 6° after TDC and stays open for 138°.

Please note that the angular degrees given here are approximate values, as the crankshafts are reworked by hand.